Modulating valve



Oct. 23, 1945. 'H L BE L Y 2,387,225

MODULATING VALVE" Filed Nov. 30/ 1942 Patented Oct. 23, 1945 UNITEDSTATE S PATENT OFFICE Electrimatic Corporation,

Illinois a corporation of Application November 30, 1942, Serial No.467,299

9 Claims.

This invention relates to'a modulating valve, and more particularly toan improved valve for regulating fluid flow.

One feature of this invention is that it provide an improved modulatingvalve; another feature of this invention is that it'provides structurewherein a diaphragm may be used as the actuating member for the mainvalve; still another feature of this invention is that the pilot valveaction is very stable; yet another feature of this invention is thattheeffect of pressure variations of the claimed herewith is primarilyconnected with this latter type of valve, conventionally called amodulating valve.

In order to have modulating action, the position of the main valve mustin some-way affect the control mechanism or pilot valve. That hasheretofore been accomplished commercially by having the seat or orificewith which the pilot valve cooperates carried by the main valve, or bymechanism associated with the main valve. This arrangement is not welladapted to use with diaphragm actuating means, however, and presents anumber of problems in construction and operais sealed to the main valvemember II, by any appropriate means, here shown as a gasket 25, and athreaded cap 26. The casting 23 carries still another casting 21, allthree of these castings cooperating to form the valve body as a whole.

The valve body is surmounted by the actuating portion of a controlarrangement. This is here shown as a conventional arrangement intendedto be operated by fluid pressure, as fluid from a control thermostat.The control fluid is admitted through the pipe 28, to the housing 29,where its pressure is exerted on the top of member 30, in opposition toa spring 3|, so that the position of the member 30 and of the rod 32fastened to it are a function of the pressure of the control tion. Theinvention disclosed herewith enables modulating action even though theorifice with which the pilot valve cooperates is fixedly mounted in thevalve body. This is accomplished by having the control means arranged tomove the pilot valve in one direction against the force of a spring, andarranging the spring so that the main valve position aifects its tensionor force.

In the particular embodiment of my invention disclosed herewith, thevalve is shown as comprising a main body casting l0 having an inlet IIand an outlet l2, separated by a partition I 3 having a main valve ororifice l4 therethrough. The oriflce I4 is surrounded by a bead It, withwhich packing i8 cooperates, this being carried by the main valve memberH. The members I8 and 19 are merely parts of a spider serving as a guidefor the rod 20 carried by the main valve member. Plug 2| and screw 22are merely drainage means.

The upper part of the main casting I0 i enclosed by another casting 23,these two castings being bolted or otherwise clamped together about theouter edge of a diaphragm actuating member 24, which may be of leatheror similar flexible impervious material. The center of this diaphragmfluid. A sealing arrangement is provided, in conventional manner, by aSylphon or sealing bellows 33.

Returning now to the valve body, it will be seen that an actuatingchamber 34 is provided above the diaphragm 24, and space provided aroundthe diaphragm on its under side so that it is open to pressure in theinlet of the valve. Thus, pressure in the chamber 34 tends to move thediaphragm and main valve ll downwardly, and the space beneath thediaphragm, by exposing its underside to inlet pressure, provides a forceopposing pressure in the chamber 34.

immediately above the actuating chamber 34, but sealed from it, is apilot valve chamber 35. Thebody of the valve is drilled with variouspassageways as shown. Passageways 36 and 31 lead to a restrictedpassageway 38 openlng into the actuating chamber 34; and from this pointpassageways 39 and 40 communicate, throughan orifice 4|, withthe chamber35, communication being provided from this chamber to the valve outletby the passageways 42 and 43. Since the pressure in the actuatingchamber 34 is what determines the position of the main valve,passageways .38 and 3'! form what may be termed the inlet passageway,this Joining the restricted passageway into the chamber 34 and theoutlet Dassageway, thev latter comprising a flow path inflow. Thiscomprises a pilot valve 45 cooperating with an annular bead 4B,surrounding the orifice 4|. The pilot valve is carried by alongitudinally movable rod member 41, which extends down into theactuating chamber; anda rod member 48 is adapted to force the pilotvalve down away from its seat when the pressure of the control fluidincreases sufficiently.

It will be noted that the main orifice andvalve member, the rod members41 and 48, and the pilot valve and its orifice, are all coaxial.

Both of the rod members 41 and are sealed so that there can be nomovement of fluid through the openings in which these rod members move,this being here shown as accomplished by sealing bellows 49 and 50.Fluid pressure in the chamber 34, in the particular arrangement of partsshown here, tends to move the rod member 41 up, while fluid pressure inandabove the orifice 4| tends to move the rod member 48 up, but thevalve member 45 down. Since these fluid pressures are the same and are afunction of the inlet pressure of the fluid being con- I trolled, properdesign and proportions of the parts can eil'ect a balance of forces suchthat operation of the pilot mechanism is independent of fluid pressurein the inlet of the valve. Since the pressure on both sealing bellows issuch that force exerted through the rod 48 and the upward restoringforceprovided by the spring SI, and when this restoring force hasreached .the proper value, the pilot valve 45 will have been moved backup to a position where the outlet flow bears the proper relation to theinlet flow, whereupon the partswill become stabilized and the main valvewill remain in that position. Any slight increase or decrease inpressure of the control fluid will result in a new position of the mainvalve, these bearing a predetermined relationship which can. be workedout in advance and which is independent of the pressure of the fluidbeing conit will force upward while that on the valve member is down,the effective diameters oi the sealing bellows (thediameters or theirinner convolutions) are so chosen that their two areas, when addedtogether, are equal to the area within the bead 4!, the area over whichfluid pressure is effective on the valve member 4!. These areas shouldalways hear a relation such that the area within the bead 48 is equal tothe algebraic sum of the effective areas of the sealing bellows. Thatis, if the pressure on both bellows is effective in a direction opposedto that on the pilot valve, their areas would be added with a plus sign,while it one is in the opposite direction, its area would be subtractedfrom that of the other bellows to determine the proper area for the head46. In any event, of course, all portions of the outlet passageway mustbe larger than the narrowest portion of the inlet passageway adjacent toplug 44, so that fluid can always be removed from the actuating chamber34 faster than the inlet passageway can supply it.

The main valve member l1 carries within it a fairly heavy spring II, theupper end of this spring carrying a pressure member 52. which makespoint engagement with the lower end of the rod member 41. when the partsare in the position shown, therefore, the pressures above and below theactuating diaphragm 24 are substantially balanced (since i'ull inletpressure exists on both sides), and the force of the sprin 5i and theweight oi the valve I! keep it closed. when the control arrangementreacts to a demand for fluid flow. however. the pilot valve is V pusheddownwardly by the rod member 48. and

- chamber), the diaphragm moves upwardly, carrying the. main valvemember with it, and opening the main flow passageway.- Any upwardmovement of the main valve member, however, raises the lower end of thespring BI and 'thus increases the force of its upward pressure on thepilot valve 45. The position of the pilot valve 45 is thus a function ofthedownward control trolled.

This arrangement provides a particularly good and stable modulatingvalve structure, a retarding or dash pot action being provided by theslow movement of liquid in and out of the actuating chamber 34 becauseoi. the restricted nature of the passageway 38. While this valve may bemade in any desired size, it provides a particularly importantimprovement in operation in large sized valves. 1

While I have described and shown certain embodiments of my invention, itis to beunderstood that it is capable oi many modifications. Changes,therefore, in the construction and arrangement may be made withoutdeparting from the spirit and scope or the invention as disclosed in theappended claims.

' I'claim:

l. A modulating valve 01' the character described adapted to control theflow 01' fluid under pressure, including: a valve body having an inletand an outlet and a partition separating them, the partition having amain flow opening therethrough; a main valve member arranged to controlflow through the opening; a control chamber; a diaphragm actuatingmember having one side subject to the pressure in the control chamberand its other side subject to inlet pressure;

means connecting the actuating member and the 48 for venting pressure inthe chamber; control means constructed and arranged so as to vary theflow thorugh one of said passageways in a manner to vary. the pressurein said control chamber and cause movement of the actuating member;actuating means for the control means including yieldable force applyingmeans opera-j tive thereon; and yielding means operatively connected tothe main valve member and to the control means, the connection beingsuch that movement of the'main valve member toward and away from saidmain flow opening results in the application oi a force through saidconnection in a direction to oppose the force applied by the actuatingmeans to affect flow through the controlled passageway in a mannertending to ofiset the initial variation in the pressure in the controlchamber.

2. A modulating valve of the character de-,

scribed adapted to control the flow of fluid under pressure, including:a valve body having an inlet its other side subject to inlet pressure;means connecting the actuating member and the valve.

member; a passageway connecting the control chamber to the inlet; asecond passageway for venting pressure in the control chamber; anorifice means forming part of one of the passageways, said orifice meansbeing fixedly positioned;

a pilot valve for controlling flow through said orifice means so as tovary the pressure in the control chamber; control means affecting theposition of said pilot valve, said control means including yieldableforce applying means operative on the pilot valve to actuate it in onedirection; and yielding means operatively connecting the main valve andthe pilot valve, the connection being such that initial movement of thepilot valve in a certain direction causes movement of the main valve ina direction such that forces are developed in and transmitted throughthe connection opposing movement of the pilot valve in the initialdirection, whereby movement of the main valve toward and away from themain flow opening affects fiow through the passageway having said pilotvalve controlled orifice means therein.

3. A modulating valve of the character described adapted to control theflow of fluid under pressure, including: a valve body having an inletand an outlet and a partition separating them,

the partition having a main fiow opening therethrough; a main valvemember arranged to concontrol chamber and cause movement of theactuating member; control means for moving the pilot valve, said controlmeans including yieldable force applying means operative on the pilotvalve to actuate it in one direction; spring means providing a forceopposing such movement; and means providing an oprative connectionbetween the main valve and the spring, the connection being such thatmovement of the main valve toward and away from the main flow openingvaries said 4. Apparatus of the character claimed in claim 3, whereinthe main valve and pilot valve are coaxial and said spring has one endcarried by the main valve. 3

5. Apparatus of the character claimed in claim 1, wherein the connectionbetween the control chamber and at least one of the passageways isrestricted, whereby movement of the main valve in at least one directionis retarded.

6. A modulating valve of the character described adapted to control thefiow of fluid under pressure, including: a valve body having an inletand an outlet and a partition separating them, the partition having amain flow opening therethrough; a main valve member arranged to controlflow through the ripening; a control chamher; a movable actuating memberhaving one side subject to the pressure in the control cham-- her andits other side subject to inlet pressure; means connecting the actuatingmember and the valve member; a passageway connected to the inlet; asecond passageway connected to the outlet, said passageways joining eachother; a restricted communication between the control her;

chamber and the point of juncture of said passageways; an orifice meansforming part of one of the passageways, said orifice means being fixedlypositioned; a pilot valve for controlling fiow through said orificemeansso as to vary the pressure in said control chamber and causemovement of the actuating member; control means afiecting the positionof said pilot valve, said control means including yieldable forceapplying means operative on the pilot valve to actuate it in onedirection; and yielding means operatively connecting the main valve andthe pilot valve, the connection being such that movement of the mainvalve results in the application of a force through said connection in adirection to oppose the movement of said pilot valve which caused themovement of the main valve, the position oi the pilot valve being afunction of both of the last mentioned means.

" "I. A modulating valve of the character described adapted to controlthe flow of fiuid under pressure, including: a valve body having aninlet and an outlet and a partition separating them: the partitionhaving a main flow opening therethrough; a main valve member arranged tocontrol flow through the opening; a control chamber; a movable actuatingmember having one side subject to the pressure in the control chamberand its other side subject to inlet pressure; means connecting theactuating member and the valve member; a passageway connectingthecontrol chamber to the inlet; a second passageway for venting pressurein the control chamber; a pilot therearound, flow or fluid through thisorifice afiecting the pressure in the control chamber; a-

pilot valve for controlling flow through said orifice so as to vary thepressure in the control chamcontrol means comprising a control rodmember passin through said orifice and adapted to engage said pilotvalve to affect the position thereof, said control means includingyieldable force applying means operative on the pilot valve to actuateit in one direction; and yielding means operatively connecting the mainvalve and the pilot valve, this means comprising a second rod membermovable in said opening between the two chambers, the connection beingsuch that initial movement of the pilot valve in a certain directioncauses movement of the main valve in a direction such that forces aredeveloped in and transmitted through the connection opposing movement ofthe pilot valve in the initial direction, wherebymovement of the mainvalve toward and away from the main flow opening afiects flow throughthe passageway having said pilot valve controlled orifice therein. 1 v

8. Apparatus of the character claimed in claim '7, wherein both rodmembers are coaxial and longitudinally movable and the connectionbetween the 'second'rod membe and the actuating member includes aspring.

9. Apparatus of the charactei claimed in claim the pressure of saidfluid,

HENRY BEEKLEY.

